Insulating unit



J. L. GREGG INSULATING UNIT June 12, 1934.

Filed April '7, 1952 five/ n fir: Ezzza92l G219 Patented June 12, 1934 UNITED STATES mesne assignments, to Reynolds Research Gorporation, New York, N. Y., a corporation of Delaware Application April 7, 1932, Serial No. 603,729

PATENT OFFICE 3 Claims. (01. 154-45) This invention relates to aninsulating material and more particularly to a material taking advantage of the non-radiating qualities of a highly polished metal surface. Reference should be had to applicants copending application serially numbered 514,516, filed February 9, 1931, and entitled Insulating unit, for a full discussion of heat conduction, radiation and connection.

Propagation of heat from or to a body is ac- 0 complished by conduction, convection and radiation. It is with respect to the latter property applied to polished metal that the present invention is chiefly concerned.

Bodies having a black surface are the best radiators of heat; A perfectly black surface absorbs all of the radiating heat energy impinged thereagainst. A body having a black surface and absorbing all of the radiant heat striking it is said to have an absorptivity of unity. Bodies light in color are less diathermic to the radiant form of heat. The absorptivity thereof is given in a fraction of unity.

The emissivity of a given body is stated in terms of the radiating power of a perfect radiator or a black surfaced body. Since a surface which is a good radiator is also a good absorber, the emissivity is exactly equal to the absorptivity.

Tests have shown that a buffed white surface, such as that produced by the application of a white lacquer, has an emissivity or an absorptivity of .80 to .95 compared to 1.00 of a black surface. Similar tests have shown that a highly polished metal surface has an emissivity of .10. Stated differently, a bright metal surface absorbs r and re-radiates but ten per cent of the heat radiated thereto, and radiates but ten per cent of the heat that would be radiated by a black body at the same temperature.

It is an object of the present invention to advantageously incorporate this property of a polished metal surface with a material of low heat conductivity to provide a highly efficacious combination, resistant to both heat conduction and heat radiation.

Another object of the present invention is to provide an insulating unit comprising a body of insulating material having a surface which is impervious to both the emanation and absorption of radiant heat energy.

Another object of the present invention is to provide an insulating unit having walls of an insulating material with a bright metallic surface, there being enclosed spaces between such walls.

Still another object of the present invention is to provide a new insulating unit having walls of an insulating material with a metal foil applied to the surface thereof, there being enclosed spaces intermediate the walls.

A further object of the present invention is to provide an insulating unit such as the above adapted to be assembled with similar units to enclose a space against a transfer of heat therefrom or thereto.

Another object of the present invention is to provide a unit for the insulation of heat and comprising outer walls of a compound formation embodying an insulating sheet faced with highly polished metal sheets and interior walls of a highly polished metal sheet.

Other desirable objects of the present invention will be made apparent in the following description where like reference characters indicate similar parts as shown in the accompanying drawing hereby made a part of this specification. The description of the invention is to be read conjointly with the accompanying drawing in which:

Figure 1 is a front elevation of one embodiment of the invention;

Figure 2 is a side elevation of the device shown in Figure 1 with parts broken away to illustrate 0 details of construction; and v Figure 3 is a sectional view of a different form of the invention.

Reference to the drawing discloses a number of panel walls 10 which are separated one from 0 another by spacer members of a non-diathermic material. The invention, as illustrated in Figures 1 and 2, comprises three voids 11, each to be in turn divided into two compartments 12. The closure about each void 11 is an independent structure.

Walls 10, as shown, are identical in structure.

Each wall comprises a layer of heat insulating material 13 intermediate two sheets of metal foil 14. Another highly polished metallic surface may be substituted for the foil.

Around the edge of the unit are thin spacer members 15 to be secured in place by any suitable means, such as by an adhesive material. The spacer members 15 in the present instance are formed of wood, but any rigid non-diathermic material will serve as well. The spacers 15 are flush with the edges of the congruent panel walls so that the edges of the units may be set flatly together upon the flat surface thus formed when assembling a number of them into a structure wall.

To add to the strength of the unit, additional spacer members 16 are positioned as central supports for the voids. Material not unlike that composing the edge spacer may be utilized in the reinforcing strips 16. The strips 16 also may be secured in anormal position between the panel walls 10 in the same manner as are the members 15, anchorage being had to the panel on either side.

The plan dimensions of the metallic surfaced panels determine the number of spacer members space relation.

Where the unit consists of a plurality of voids or closed spaces in juxtaposition, it is desirable to place the reinforcing elements 16 of the different complemental voids in a single plane normal to that of the panel walls, and as is shown in Figure 1.

The insulating unit as described and illustrated takes full advantage of all of the impediments to heat propagation. There is very little turbulence of the gas in the voids between the panels of the structure, hence the transfer of heat by convection is neglible. The spacer strips are thin in body and are, therefore, capable of but slight heat conduction. The third means of heat transfer, namely, radiation, is substantially avoided by the use of the bright metallic surfaces on the panels;

That form of the invention shown in Figure 3 is but slightly changed in structure from that of the above described form, the difference residing in the structure of the inner walls.

Spacer members 20 and 21 may be of the same material and arranged in the same manner as are the members 15 and 16 shown in Figure l. Opposite outer walls 22 of the unit are composed of a sheet of heat insulating material 23 faced on either side by highly polished metal sheets 24. The intermediate walls 25 are made from a single sheet of polished metal.

This form of the invention is held in assembly either by a suitable adhesive or by other means such as brads or tacks. After the spacer members for partially enclosing a void are secured in place, the walls 25, if they be thin and flexible, are stretched tautly across the common edge of those membersand there fastened. The next void is then provided by adding other spacer members 20 and 21 and the metallic wall 25 in the same fashion. Protection to the inner walls is had by the spacer members 20 and the reinforced walls 22.

The latter described form of the invention has advantages because of economic reasons in that only a single sheet of metal is necessary for the inner walls. It is also advantageous in that no heat conducting media such as the reinforcingsheet is within the inner walls of the unit.

What I claim as new, and desire to secure by Letters Patent of the United States is:

1. An insulating unit comprising inner walls and outer walls mutually arranged in selected planes and presenting perpendicularly alined edges, said outer walls including a layer of insulating material intermediate two metal foil layers and said inner walls comprising a sheet of metal foil, and spacing members of insulating material in the form of thin strips with oppositely disposed narrow edges, part of said spacing members being placed intermediate said alined edges with the narrow edges engaging the opposed walls, and the other of said spacing members being similarly placed intermediate said walls away from their edges.

2. An insulating unit possessing lateral squared edges arranged about a polygon, and comprising inner walls and outer walls selectively spaced in alined positions normal to said edges, said outer walls including a sheet of insulating material 100 with sheets of metal foil having a; highly polished surface upon opposite faces thereof and said inner walls being of a single sheet of polished metal foil, and spacingmembers in the form of thin heat insulating strips with narrow longitudinal edges oppositely disposed, said spacing members being placed intermediate said Walls with the narrow edges contiguous to said metal foil with a part thereof arranged within the plane of said squared edges hermetically enclosing the spaces between said walls and providing a flat surface for the edges of said unit.

3. An insulating unit having a normal squared edge providing a number of adjoined faces enclosing a polygon, and comprising inner and out,- er walls of identical polygonal configuration, and spacing members of a heat resistant material in the form of thin strips with narrow longitudinal opposed edges, the outer walls comprising an insulating base with sheets of polished metal foil 12 secured to opposite faces thereof, said inner walls including a single sheet of polished metal foil, and said spacing members adhesively assembled to said walls with their narrow edges placed adjacent to opposed sheets of metal foil, part of said spacing members being disposed within the faces of said edge to hermetically enclose the spaces between said walls and to provide a flat surfacefor said faces, and the other of said spacing members being placed in assembly with said walls away from the edges of said unit.

JAMES L. GREGG. 

